ph swings

[low riderr]

could adding bioclean to the system cause ph swings? for the past few weeks the ph will go from low 8.s in the am to as high as 8.6 tonight after work.its not normally this high but its been getting worse as time goes on. is this the sighn of a bad ph probe? most everything is looking ok except one sps colony and it was fine till i turned the lights out for 3 days,when i turned the lights back on it was lookin ill. temp is 76.0 to 77.0
alk is 7.0 t0 8.0
cal is 390 to 430
mag is 1300 to1450 #s from the past 6 months. any ideas thanks

 

[diverdick]

Do you dose any additives? (i.e. alk sups?)

BTW, I would avoid the alk dip to 7.0

PS: Why lights off?

 

[Eastamherstbias]

I am all over the place with ph.

 

[diverdick]

I am all over the place with ph.

I would suggest the variation you posted here is an instrument problem. pH cant behave like that in the amount of time listed.

 

[sf_ramsden]

I would suggest the variation you posted here is an instrument problem. pH cant behave like that in the amount of time listed.

Are you dosing something to make your pH jump up and down like that? It almost seems like it is a constant thing every half hour or so it spikes up. Maybe there is a doser running every half hour?

 

[Eastamherstbias]

Nope no dosing. I do have three tanks flowing into the basement sump. I thought the graph was normal. Now I will need to investigate. It was correctly calibrated.

 

[Eastamherstbias]

 

[diverdick]

Eastamherstbias

Back to basics in terms of trending instruments, the first thing that comes to my mind when I see any trend that looks like those, noise must be considered. The sharp peek to peek changes are suspect for certain. You can also notice areas of the trends that "look normal" between the high frequency, high amplitude variations. I have never had probes in any of my systems (old school here) but, I have studied instrument data trends for years.

A closer look at your pH & ORP trends shows they "misbehave" at the very same times. For example, both trends become more "normal" at ~ 3:00 and return to "unusual" at ~ 10:00. that smaks of some sort of induced problem such as flaky connection, induced current or the like. IMHO, worth looking into.

You noted calibration in your post, that really is not the issue IMHO. It looks more like a signal influence in the trend. In all trending systems, the PC (or PLC) has a setting (most likely factory set in this case) to pick data in a scheduled frequency. for example, if there is an instrument that changes frequently, fast data speeds are necessary. In this case, data is likely moved to memory at a slower pace (in minuets mos likely)

In the end, something is amiss.

--Rich

PS: sorry to digress the post low rider

 

[Conesus_Kid]

 

[Willistein]

Are your pH and ORP measured by the same probe? If so, the probe is malfunctioning. What is different after 10 pm and before 2 pm? A different light coming on over the sump?

 

[diverdick]

I am curious if there is an electrical influence from a device like a heater, water pump etc. that may put a small amount of current in the system, that ultimately affects these probes????

curious for sure.

 

[low riderr]

think i found my problem.dug out another ph meter and tested the tank with that,it read 8.0 while the probe was reading 8.6 late last night. this am 7.9 with meter,probe was 8.4.i am gonna recal. if that dosnt fix it its time for a new probe. i do dose but everything has been the same for almost a year now . the amount i dose and the numbers that i get when i test vary very little till now. here is my schedule, kalk in top off -daily dose of alk 50ml.,cal.50ml.daily,and mag.90ml almost daily. thanks guys

 

[tmz]

With failoing probes, ph monitors tend to drift upward. Swings may in part be related to interference even outside thewater via ballasts or draw on outlets. Why do you keep the oprp in the 600 range? Are you dosing ozone?

 

[Eastamherstbias]

Why do you keep the oprp in the 600 range? Are you dosing ozone?

If this question is for me. I am not dosing ozone. My main tank lights are 2-12 every day and my frag tanks are 12pm-5pm, 12am-5am. I will look into the cause of my issues. I have the three probes in a three probe holder in the sump. I may move them into the frag tank to see if that changes anything.

 

[Gravesj1s]

I was told to take the probe out of the tank or sump,take a glass filled with tank water and imerge the probe to see if the readings were the same.If they differ from tank to glass its likely caused by stray voltage.

I did this recenty and seen different readings amongst the two but could not seem to identify what was causing it.

 

[tmz]

Eastam,
Something is wrong with those orp readings? Without ozone or hydrogen peroxide ,I'd expect 260to 320or so.

 

[Eastamherstbias]

Well I was getting a shock in the three basement tanks so I investigated. Two hours later, I removed:

UV, maxi jet and a 250w heater. They were all independently shocking.

 

[IronMan72]

I've read that having the ORP probe and pH probe too close to each other may cause interference. I've had a noise problem with my controller that I traced to the ground of the controllers RS-232 line. I just disconnect the RS-232 line from the computer unless I'm changing the program but this means that I can't do logging like you are. Neptune sells an opto-isolator to eliminate this problem but I never bothered.